层板复合材料的疲劳剩余刚度统计分布模型

在分析现有关于层板复合材料疲劳剩余刚度衰退模型的基础上，根据层板复合材料在疲劳载荷作用下刚度衰退变化的现象，研究了疲劳载荷对层板复合材料刚度衰退的影响，建立了一个新的、更为合理的用于描述层板复合材料在常幅疲劳载荷作用下的刚度衰退模型，导出了剩余刚度统计分布的表达式，给出了确定模型参数的方法。为验证该模型，设计了几组测试实验，并利用试验结果对模型参数进行了估计。利用该统计分布模型，可以预报层板复合材料在给定应力水平的疲劳载荷作用下循环指定周次时剩余刚度的统计分布。实验数据表明，理论预报和实验结果符合得是很好的。

A New Fatigue Residual Stiffness Statistical Distribution Model for Composite Laminates

Based on the analysis of the existing models on the stiffness degradation of composite laminates and from the phenomena of stiffness degradation of composite laminates under fatigue loads, a new and more reasonable statistical distribution model of the fatigue residual stiffness for composite laminates has been derived, which relates the stiffness degradation to the fatigue cycles. In the paper, the procedure is given for determination of the parameters in the model. By the use of this model, the statistical distribution of the residual stiffness of composite laminates can be predicted when the fatigue cycles are given. A experimental test program has been conducted to generate meaningful data for verification with typical composite laminates and the parameters in the model are estimated by using the experimental data in the proposed parameters procedure. It is shown that the correlation between the theoretical predictions on the residual stiffness statistical distribution and the experimental results is outstanding.